Dart front disk service- any tips?? Basic questions...

Plain ol' dot 3 is fine for me so long as its fresh, not from a container that has been opened months or years ago. LOL
You'll need to wash the bearings to inspect them. If you do find a bad bearing you can know the grease reservoir between the bearing is contaminated. This means everything gets washed and new grease applied.
If you have ever added brake fluid, closing the calipers can overflow the master cylinders reservoir. If I was replacing hoses I wouldn't push any old fluid back toward the master cylinder. I would drain all of it. With all back pressure removed you should be able to close the calipers with minimal effort. If the pistons do go home easy enough and their dust boots are intact, they could be just fine. If the fluid that comes out of the caliper contains any debris at all ( some discoloration is typical ) you can just about bet the piston and cylinder wall is rusty and may cause the caliper to stick. These calipers are easy to rebuild. Rebuilt replacements are cheap enough too.